In this short paper notes and descriptions are offered of four new and two already known species of the Tetrathemine genus Nannophlebia Selys, all from the Moluccan islands and New Guinea.I have found that the specific characters of the genotype, lorquini Selys, as they were apprehended up to this time, might give rise to confusion with allied species. Therefore, I have in this paper also given a re-description and figures of the two sexes of this species, including it in a new key to the identification of all species at present known from the Moluccas.The sexes are often very difficult to correlate in this genus. Our collections contain no less than six species which I have been unable to locate : one from the Banggai Islands, one from Japen (off northern New Guinea), and four from the mainland of New Guinea. All of these are probably new to science, but as there seems little prospect of obtaining the males, I have refrained from describing them and giving them a name.All members of Nannophlebia are found near running water, small clear streams and brooks in virgin forest affording the most suitable breeding places. Because of the apparently limited range of nearly all species, representatives are but rarely found in collections. Apart from this, the freely flying males are easily overlooked insects owing to their cryptic green-andblack colouring and their habit of keeping to dense foliage in close vicinity of their breeding place. They fly only short distances and rest on projecting twigs, usually in such inaccessible places like dark ravines and other damp situations. The females, on the other hand, are more often seen while ovipositing over the ripples in the stream bed. They sometimes congregate during this act in some numbers and under these circumstances are more easily